TransactionManager

DAO
org.springframework.jdbc.datasource.DataSourceTransactionManager

src/main/resources/java/com/wwq/bookshop/JdbcBookShop.java

@@ -21,6 +21,7 @@ public void purchase(String isbn, String username) {
 		Connection conn = null;
 		try {
 			conn = dataSource.getConnection();
+			conn.setAutoCommit(false);
 
 			PreparedStatement stmt1 = conn
 					.prepareStatement("SELECT PRICE FROM BOOK WHERE ISBN = ?");
@@ -44,7 +45,15 @@ public void purchase(String isbn, String username) {
 			stmt3.setString(2, username);
 			stmt3.executeUpdate();
 			stmt3.close();
+
+			conn.commit();
 		} catch (SQLException e) {
+			if (conn != null) {
+				try {
+					conn.rollback();
+				} catch (SQLException e1) {
+				}
+			}
 			throw new RuntimeException(e);
 		} finally {
 			if (conn != null) {

src/main/resources/java/com/wwq/bookshop/TransactionalJdbcBookShop.java

@@ -0,0 +1,44 @@
+package com.wwq.bookshop;
+
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.core.support.JdbcDaoSupport;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.TransactionDefinition;
+import org.springframework.transaction.TransactionStatus;
+import org.springframework.transaction.support.DefaultTransactionDefinition;
+
+public class TransactionalJdbcBookShop extends JdbcDaoSupport implements
+		BookShop {
+
+	private PlatformTransactionManager transactionManager;
+
+	public void setTransactionManager(PlatformTransactionManager transactionManager) {
+		this.transactionManager = transactionManager;
+	}
+
+	@Override
+	public void purchase(String isbn, String username) {
+		// TODO Auto-generated method stub
+		TransactionDefinition def = new DefaultTransactionDefinition();
+		TransactionStatus status = transactionManager.getTransaction(def);
+		try {
+			int price = getJdbcTemplate().queryForInt(
+					"SELECT PRICE FROM BOOK WHERE ISBN = ?",
+					new Object[] { isbn });
+			getJdbcTemplate().update(
+					"UPDATE BOOK_STOCK SET STOCK = STOCK -1 "
+							+ "WHERE ISBN = ?",
+					new Object[] { isbn });
+			getJdbcTemplate().update(
+					"UPDATE ACCOUNT SET BALANCE = BALANCE - ? "
+							+ "WHERE USERNAME = ?",
+					new Object[] { price, username });
+			transactionManager.commit(status);
+		} catch (DataAccessException e) {
+			transactionManager.rollback(status);
+			throw e;
+		}
+
+	}
+
+}

src/main/webapp/WEB-INF/applicationContext.xml

@@ -24,9 +24,14 @@
 		<property name="username" value="weiqingwang"/>
 		<property name="password" value="wwqwwq"/>
 	</bean>
+	<bean id="transactionManager"
+		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
+		<property name="dataSource" ref="dataSource"/>
+	</bean>
 	<bean id="bookShop"
-		class="com.wwq.bookshop.JdbcBookShop">
+		class="com.wwq.bookshop.TransactionalJdbcBookShop">
 		<property name="dataSource" ref="dataSource"/>
+		<property name="transactionManager" ref="transactionManager"/>
 	</bean>